Why driveway expansion joints need caulking — and how often to reseal

By Jake Wiles, owner · The Best Caulking & Restoration of Omaha · Updated August 2026

The joints in your driveway, sidewalk and patio aren't decorative — they're where the concrete is designed to move. When the filler in those joints rots out or the old caulk pulls away, water goes straight down under the slab. In Nebraska, that water freezes, heaves the concrete, and leaves you with the tilted, cracked, "trip-hazard" driveway that costs thousands to replace. Caulking the joints is the cheapest concrete repair there is, and it's the one most homeowners skip.

What the joints are for

Expansion joints are the wider gaps (usually with a fibrous or foam filler) between the driveway and the garage slab, the sidewalk and the street, or between large pours. They let the concrete expand in summer without pushing against itself. Control joints are the shallow grooves cut into the surface that tell the concrete where to crack. Both need to shed water, and neither does once the filler fails.

What happens when they're open

1. Water runs into the joint every time it rains or the snow melts.
2. It saturates the base under the slab — the gravel and soil the concrete sits on.
3. The base freezes and expands, lifting the slab unevenly. Thaw, and it settles — often lower than before, as the water has washed fines out.
4. The slab cracks or tilts. Edges spall, corners break, and the joint gets wider, which lets in more water.

What a proper caulking job includes

• Removing the old filler and caulk down to clean concrete — not caulking over rotten fiberboard.
• Backer rod sized to the joint, so the sealant has the right depth-to-width ratio and can stretch instead of tearing.
• A self-leveling polyurethane or silicone sealant rated for concrete and for Nebraska temperature swings — not painter's caulk, not hardware-store "concrete crack filler" in a squeeze tube.
• Tooling the joint so it's slightly concave and sheds water.
• Cracks sealed at the same time. A crack is a joint you didn't plan for. Same treatment.

We use the same commercial-grade sealants on residential driveways that we use on parking garages and commercial flatwork. It's literally in our name. Caulking in Omaha →

How often to reseal

Walk the driveway every fall. If you can see a gap between the sealant and the concrete, or the sealant is cracked, hard or missing, it's time. Resealing the joints is a small job; replacing a heaved driveway is not.

While we're there

Joint caulking pairs naturally with concrete crack repair and sealing, step and porch repairs, and penetrating sealer on patios and garage floors. One trip, one estimate, and the invoice matches it.